This invention relates generally to doors, door panels and door closure means. Many types of doors are known in the prior art; most utilize a handle, a locking mechanism in combination with the handle, and a pair of hinges. Additionally, several other non-essential elements may be utilized, such as a latch, a self-closing mechanism, a window or windows, as well as other components occasionally incorporated into the door. Because of the multitude of moving and non-moving parts, and because of the wide variety of functions which doors are expected to serve, doors are found to exist in infinite variety, each suited to a given set of specific needs.
Doors containing one or a plurality of panels have been used wherein said panels may be comprised of many different materials. Representative examples of materials from which door panels have been made include wood, metal, cloth, plastic, and similar substances. The substance from which such door panels are made is chosen depending upon the functions that each panel is to serve. For example, the material comprising each panel is frequently chosen to provide a secure closure means or to serve as a decorative and durable security device. Alternatively, a panel comprised of screen material can be used where privacy is not required and adequate ventilation is a necessity. Frequently a pair of panels is used, wherein one panel is comprised of any pliable substance, and a second is comprised of a screen. As such, the combination is useful to provide privacy, and adaptable to provide adequate lighting and/or ventilation. Various sizes and shapes of panels have been utilized, depending upon the size of the object passing through the door, the overall dimensions of the system in which the door is contained, the frequency of use, and the durability desired.
Similarly, closure means have been comprised of a variety of materials, including springs, self-closing hinges, pulley means, and mechanical means. The means for closing doors in the prior art have typically been bulky or burdensome, requiring the user to close the door manually or to activate a complicated mechanical device to close the panels. Additionally, such closure means and doors did not open and close quickly to permit fast ingress and egress cycles. Further, such prior art doors and closure means typically did not operate to permit safe equalization of pressure found on both sides of the door, when the pressure differential between sides was extremely great. Rather, a tremendous pressure differential between the sides of a door placed stress and strain upon the material of the door panel, the hinges, the closure mechanism and the locking mechanism. Finally, breakage of one of the above-mentioned components occurred, allowing the pressure to equalize.